Meeting End-to-End QoS Challenges for Scalable Flows in Heterogeneous Multimedia Environments

Abstract

Many distributed audio and video applications exhibit robusmess in adapting to fluctuations in the delivered quality of service (QoS). By trading off temporal and spatial quality to available bandwidth, or manipulating the playout time of continuous media in response to variation in delay, audio and video flows can be kept meaningful at the playout device with minimal perceptual distortion. In this paper we introduce Dynamic QoS Management (DQM) for the control and management of multi-layer coded flows operating in heterogeneous multimedia networking environments. Two key techniques are proposed to meet the challenge of supporting scalable flows over multimedia networks: i) Dynamic Rate Shaping, which is a novel source-based QoS filter for manipulating the rate of MPEG-coded flows, matching it to the available network resources while minimising the distortion observed at the receiver; and ii) an Adaptive Network Service, which offers "hard" guarantees to the base layer of multi-layer coded flows, and "fairness" guarantees to the enhancement layers based on a new bandwidth allocation technique called Weighted Fair Sharing.